Lamp construction



`Fune 1l, 1963 G. A. KNAPP 3,093,320

LAMP CONSTRUCTION Filed Nov. 1. 1960 zo 1li?" INVENTOR. will 7 GEORGE A. KNAPP 'zq'aas BY 3,693,320 LAMP CONSTRUCTIN George A. Knapp, De Witt, NX., assigner to R. E. Dietz Company, Syracuse, NSY., a corporation of New York Filed Nov. 1, 1960, Ser. No. 66,677 4 Claims. (Cl. 24R-8.2)

This invention relates generally to lamp constructions, and has particular reference to an improved structural arrangement for a vehicle clearance or marker lamp of the type commonly used on trucks, trailers, busses and the like. It will be apparent as the description proceeds, however, that the construction contemplated by the invention can be utilized in other types of lamps, vehicular or otherwise, and therefore `it is not intended to restrict the invention to a particular type of vehicle lamp.

In accordance with the foregoing, the primary object of the invention is to provide a lamp of the character described having an improved bulb mounting and electric-al Contact arrangement.

Another important object of the invention is to provide a lamp of the character described having a simplified bulb -socket construction both as to the number of component parts and as to ease of assembly during manufacture.

A further important object of the invention is to provide a lamp of the character described which will operate reliably over a long period of time without the necessity for repairs or replacement.

Other objects and advantages of the invention will become apparent from the following detailed description thereof read in conjunction with the accompanying drawings which illustrate a representative embodiment of the invention for the purpose of disclosure.

In the drawings:

FIGURE 1 is a top plan view `of a vehicle clearance or marker lamp embodying the invention;

FIGURE 2 is a side elevation of the lamp;

FIGURE 3 is a top plan view of the lamp with the lens removed;

FIGURE 4 is a vertical longitudinal section through the lamp taken substantially along line 4 4 of FIG- URE 1;

FIGURE 5 is a top plan View of the lamp base member only;

FIGURE 6 is a vertical transverse section through the lamp taken substantially along line 6-6 of FIGURE l;

FIGURE 7 is a side elevation of the insulating plate of the lamp;

FIGURE 8 is a top plan View of the insulating plate and bulb contact strip assembly; and

FIGURE 9 is a fragmentary Vertical transverse section through the lamp taken substantially along line 9 -9 of FIGURE 3.

Referring now to the drawings, wherein like reference numbers designate the same part in each of the Views, the lamp includes `a base member 15 and lens 16, the base member being secured to the vehicle body as by bolts (not shown) which pass through mounting holes 17. A gasket 1S is preferably interposed between the base member and vehicle mounting surface. The base is formed with a shallow outwardly projecting peripheral ilange 19 having a groove 2d in which is seated an elastic sealing or Oring 21. The ring 21 serves to detachably secure the lens to the base 'and provide a seal therebetween, and for a more detailed description of this particular portion of the lamp reference is made to U.S. Patent No. 2,855,498, issued October 7, 1958, to the applicant herein.

Within the peripheral flange 19, the base member is formed with a pair of projections or bosses 22 having Patented June l1, 1963 "lee semi-cylindrical seats 23 that comprise the lower portions `0f sockets for a pair of lamp bulbs 24. The projections 22 are integral with the base member, which is preferably a casting, and are spaced from one another as best `shown in FIGURE 5. The axes of the semi-cylindrical seats 23 are colinear and parallel t-o the longitudinal axis of the base.

A single cap member or plate 25 for-ms the upper portion of both of the bulb sockets and, to this end, the cap bridges the space between the projections 22 and is formed at its ends with semi-cylindrical seats 26 complementing the seats 23, see FIGURES 4 and 9. The cap is secured to the projections 22 by any suitable means such as rivets 27. The lamp bulbs 24 are preferably of the bayonnet type, and grooves 28 are provided along the upper edges of each seat 23 to accommodate the bayonnet lugs on the bulb base as the latter is being inserted into the bulb socket. When fully inserted, the bulb is rotated in the usual manner and the lugs seat in aligned notches 29, 30 formed in the base projections and cap, respectively, FIGURES 3 and 5.

An insulating plate 31 of iberboard or plastic is mounted in upright position in the space between the bulb sockets, the plate being located approximately midway between the confronting ends ofthe sockets at right angles to the axes thereof, The insulating plate supports a spring contact strip 32, to be described, and is maintained in upright position by the turned down edges of a pair of side projections 33 on the cap member 25, which projections overlie the upper edge of the plate, FIGURES 3, 6 and 9. The lower edge of the plate is positioned between a pair of shallow, elongated bosses or ridges 34 formed integrally with the base member 15', and a short connecting ridge 35- projects into a notch 36 in the lower edge of the plate to prevent endwise movement thereof.

The contact strip 32 is a substantially U-shaped piece of light spring metal having outwardly flared leg portions as best shown in FIGURE 8. The center section of the contact strip is received in a notch 37 provided in a side edge of the insulating plate 31 and is secured to the plate by the stripped end of an insulating conductor 38 passing through registering holes 39 in the contact strip 32 and plate 31 and secured by swaging the stripped end. With this arrangement, the legs of the contact strip are disposed in substantially horizontal position on the opposite sides of the insulating plate, and a rectangilar window 40 is provided in the plate opposite the free end portions of the legs for a purpose to be described.

When a lamp bulb is inserted in a bulb socket, the center terminal 41 on the bulb base, FIGURE 4, moves into engagement with the leg of the contact strip adjacent the inner end of the socket and pushes it towards the insulating plate. Since the bayonnet lugs on the bulb base must be pushed beyond the end of the socket before the bulb can be rotated to seat the lugs in the notches Z9', 30, the terminal 41 will push the contact strip leg a short distance into the insulating plate window 4t] which is provided for this purpose. Thereafter, when the bayonnet lugs on the bulb are rotated into registry with the notches 29, 30, the spring bias of the contact strip leg moves the bulb outwardly a Short distance to seat the lugs in the notches, and this spring bias serves to hold the bulb in seated position as well as to insure good electrical contact between the terminal 41 and contact strip leg, see FIGURE 4.

The conductor 38 passes through a rubber grommet 42, FIGURE 3, that is mounted in a hole 43y in the bottom of the base member, and is connected to a suitable source of electrical energy such as the Vehicle battery to deliver current to the lamp bulbs. The U-shaped contact strip 32 forms a parallel circuit for the bulbs so that if one bulb should burn out the other can still operate, the circuit for both bulbs being completed through their other terminals to the base of the -larnp which is grounded to the vehicle body by means of its att-achment bolts (not shown).

From the foregoing description, it will be apparent that the lamp construction `of the invention provides for a simplified and highly practical bulb socket and electrical contact arrangement. As will also be [apparent to those familiar with the art, the invention may be embodied in other specific vforms without departing from the spirit or essential characteristics thereof. The embodiment disclosed is therefore to be considered in all respects as illustrative rather than restrictive, the scope of the invention being indicated by the appended claims,

What is claimed is:

l. A lamp having two incandescent bulbs comprising a base member of conducting material, means integral with said base member forming the lower portions of a pair of spaced, coaxial lamp bulb sockets, a at insulating plate, means forming the upper portions of said bulb sockets and engaging said insulating plate to hold it in upright position centered between the confronting ends of the bulb sockets, said plate being disposed at substantially right angles to the axes of said sockets, a spring contact strip narrower than said plate and being secured to said insulating plate, said strip having portions extending along the opposite sides of the plate for engagement with the base terminals of the lamp bulbs mounted in said sockets, said contact strip portions being sprung outwardly from said insulating plate when said bulb sockets are empty and being pushed inwardly into substantially parallel relation to the plate when bulbs are mounted in the sockets, and an electrical conductor connected to said contact strip to deliver current thereto.

2. Structure as defined in claim 1 wherein said insulating plate is formed with a centrally located aperture wider than said strip and Iadapted to receive said outwardly sprung contact strip portions when the latter are pushed inwardly by the bulbs.

3. In a vehicle clearance lamp having a pair of incandescent bulbs: a base member having a bottom portion of conducting material adapted to be mounted on the vehicle body, a lens secured to `said base to cover the bottom portion, means integral with said base bottom portion forming between said lens and said bottom portion the lower portions of a pair of spaced bulb sockets having colinear axes, a flat insulating plate, means forming the upper portions of said bulbs sockets comprising a single cap member secured at opposite ends to said socket lower portions and bridging the space therebetween, means on said cap member engaging said insulating plate to hold it in upright position centered between the confronting ends of said bulb sockets, said insulating plate being disposed at substantially right angles to the axes of said sockets, a narrow spring contact strip fixed to one edge of said insulating plate and having portions extending along the opposite sides of the plate for engagement with the base terminals of said pair of lamp bulbs when the latter are mounted in said bulb sockets, and an electrical conductor connected to said contact strip to deliver current thereto.

4. In `a vehicle clearance lamp having a pair of incandescent bulbs: a dished base member of conducting material adapted to be mounted on the vehicle body, a lens mounted on said base member and defining therewith an enclosed lamp bulb chamber, `means within said chamber and integral with said base member forming the lower portions of a pair of spaced bulb sockets having colinear axes, a single cap member forming the upper portions of both of said bulb sockets, said cap member bridging the space between the sockets and being fixed at opposite ends to said lower socket portions, a generally rectangular flat plate of insulating material mounted in upright position between the confronting ends of said bulb sockets, said plate being disposed at substantially right angles to the axes of said sockets, means on said cap member and base engaging the upper and lower edges of said insulating plate to hold it in upright position, coacting means on said base -member and insulating plate to hold the latter against lengthwise movement, a spring contact strip narrower than said plate and fixed to one edge of said insulating plate, said strip having portions extending along the opposite sides of said plate for engagement with the base terminals of lamp bulbs mounted in said sockets, said contact strip portions being sprung outwardly from said insulating plate when said bulb sockets are empty and being pushed inwardly into substantially parallel relation to the plate when bulbs are mounted in the sockets, said insulating plate being formed with a centrally located aperture Wider than said strip and adapted to receive said outwardly sprung contact strip portions when the lat-ter are pushed inwardly by the bulbs, and an electrical conductor connected to said contact strip to deliver current thereto.

References Cited in the tile of this patent UNITED STATES PATENTS 1,325,007 Douglas Dec. 16, 1919 1,528,332 Hemmeter et al. Mar. 3, 1925 1,590,016 Godley June 22, 1926 2,689,945 Benander Sept. 21, 1954 2,754,410 Thielorn July l0, 1956 2,855,498 Knapp Q Oct. 7, 1958 

1. A LAMP HAVING TWO INCANDESCENT BULBS COMPRISING A BASE MEMBER OF CONDUCTING MATERIAL, MEANS INTEGRAL WITH SAID BASE MEMBER FORMING THE LOWER PORTIONS OF A PAIR OF SPACED, COAXIAL LAMP BULB SOCKETS, A FLAT INSULATING PLATE, MEANS FORMING THE UPPER PORTIONS OF SAID BULB SOCKETS AND ENGAGING SAID INSULATING PLATE TO HOLD IT IN UPRIGHT POSITION CENTERED BETWEEN THE CONFRONTING ENDS OF THE BULB SOCKETS, SAID PLATE BEING DISPOSED AT SUBSTANTIALLY RIGHT ANGLES TO THE AXES OF SAID SOCKETS, A SPRING CONTACT STRIP NARROWER THAN SAID PLATE AND BEING SECURED TO SAID INSULATING PLATE, SAID STRIP HAVING PORTIONS EXTENDING ALONG THE OPPOSITE SIDES OF THE PLATES FOR ENGAGEMENT WITH THE BASE TERMINALS OF THE LAMP BULBS MOUNTED IN SAID SOCKETS, SAID CONTACT STRIP PORTIONS BEING SPRUNG OUTWARDLY FROM SAID INSULATING PLATE WHEN SAID BULB SOCKETS ARE EMPTY AND BEING PUSHED INWARDLY INTO SUBSTANTIALLY PARALLEL RELATION TO THE PLATE WHEN BULBS ARE MOUNTED IN THE SOCKETS, AND AN ELECTRICAL CONDUCTOR CONNECTED TO SAID CONTACT STRIP TO DELIVER CURRENT THERETO. 